Electric-arc lamp



(No Model.) 2 Sheets-Sheet 1 E. THOMSON & U. E. HARTHAN.

ELECTRIC ARC LAMP.

Patented De (No Model.) 2 Sheets-Sheet 2.

E. THOMSON & O. E. HARTHAN. ELECTRIC ARC LAMP.

No. 595,420. Patented Dec. 14,1897.

UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF SWVAMPSCOTT, AND CHARLES E. HARTHAN, OF LYNN, MASSACHUSETTS, ASSIGNORS TO THE GENERAL ELECTRIC COMPANY, OF

NElV YORK.

ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 595,420, dated December 14, 1897.

Application filed June 12, 1897.

To aZZ whom it may concern.-

Be it known that we, ELIHU THOMSON, residing at Swampscott, and CHARLES E. HAR- THAN, residing at Lynn, county of Essex, State of Massachusetts, citizens of the United States, have invented certain new and useful Improvements in Electric-Arc Lamps, (Case No. 540,) of which the following is a specification.

This invention relates to arc-lamps, and has especial reference to that class of lamps in which the arc is inclosed,and especially adapted to run on constant-potential circuits, with a resistance in the branch containing the lamp.

The invention embraces a number of improvements in the details of the construction of such lamps, adapting them to be run with small currents and providing an efficient and economical arclamp constructed and arranged as hereinafter set forth and claimed.

Referring to the accompanying drawings, Figure 1 is an elevation, partly in section, of an arc-lamp embodying detailed improvements in accordance with this invention. Fig. 2 is an enlarged detail view, in vertical section, of a modification of the dash-pot connected to the upper-carbon support. Fig. 3 is a horizontal plan view of a portion of the 0 device shown in Fig. 2. Fig. 4 is a detail view in elevation, showing the clutch mechanism. Figs. 5, 6, and 7 are detail plan views of the holding device for the inner globe. Figs. 13 and 14 are views in elevation of part 3 5 of the supporting-frame for the carbons, showing the arrangement of the outer globe and its support. Fig. 15 is an elevation, partly in section; and Fig. 16 is an elevation showing the contact-making weight or follower for the upper carbon.

Referring to Fig. 1, the lamp is shown provided with the inner tube 1, in which is located the tube 2, within which is the upper carbon 3 of the lamp, arranged to slide therein,

the upper end of said tube 2 being hinged to a piston 4, arranged to slide in the dash-pot 5, secured to the upper end of the tube 1. A

weight 6, located in the tube 2, bears on the upper end of the carbon 3 and is for the pur- Serial No. 6%,4'72. (No model.)

pose of producing a more positive action of the feed when the carbon is released. A magnet-coil 7, of insulated wire, preferably wound, so as to resist high temperature, surrounds the tube 8, within which is located a cylindrical core 9, adapted to play up and down in accordance with the attraction exerted by the magnet-coil 7. The upper end of the cylindrical core 9 is tapered or contracted, as shown, to bear against the tube 2. The core 9 is partly a solenoid-core and partly an electromagnet-core. The coil 7 is preferably inclosed by an iron casing 10, extending over the ends thereof, thereby completing the magnetic circuit around it and adding to the force exerted on the core 9. The core 9 is secured at its lower end to the tube 2. The tube 1 is secured atits upper end to the upper part of the lamp where the lamp is suspended, and the lower end of tube 1 is secured to the upper part of the casing 10.

A clutch mechanism is provided to engage the upper carbon and to move with'tube 2 and core 9 as follows: 11 11 are the jaws for clamping the upper carbon, which are pivoted to bell-crank levers 12, pivoted in turn to a cross-piece 13, which slides on guide-rods 14:, depending from a cross-piece 15, mounted on a portion 16, depending from the bottom of casing 10. The upper portion of levers 12 are bent in a horizontal direction to clear the tube 2, as shown in Fig. 6, and have their up- .per ends pivoted, respectively, to the depending arms 17 of a yoke 18, clamped to the tube 2. The tube 2 being lifted by the raising of core 9 will cause the levers 12 to be operated, thereby causing the lower or short arms of levers 12 to move upward and inward and the jaws 11 11 to be moved upward and toward each other. This will cause the upper carbon to be firmly clamped and the cross-piece 13 will be slightly raised on the guide-rods 14 simultaneously with the upward movement of the tube 2. By this means the upper carbon is separated from the lower and the arc is formed in the inner globe. YVhen the current in the coil 7 is weakened, so as to let down the core 9, tube 2 goes down with the yoke 18. The cross-piece 13 also descends, and

when it reaches the lower ends of the guiderods 14 and rests on the nuts 14 at the ends of the latter the levers 12 will be relaxed and the clamping-jaws 11 11 set free from the upper carbon 3. The carbon 3 is then fed downward by gravity and the weight 6 until the feed is checked by the resumption of the power of the coil 7, owing to the current having increased subsequently to the feed, the clutch being brought into action and the jaws 11 11 again clamping the carbon In the construction of the support for the inner globe and lower carbon and the outer globe there are two vertical tubular guiderods 19, suspended at their upper ends from a flange of the casing 10 and extending through a plate 21, which is the main portion of the bottom of a casing 22, inclosing the upper portion of rods 19, casing 10, and magnet-coil 7. In its lowered position the core 9 rests 011 the bottom of casing 22, as shown in Fig. 1. The guide-rods 19 are connected adjacent to their lower ends by a yoke 23 having a central circular opening through which extends a short tube 24, having a flange 25, located above the yoke 23. A ring-nut 26 screws on to the lower threaded end of the tube 24 and serves to clamp the latter to the yoke 23, proper insulation 27 being employed, as shown in dark lines in Figs. 1 and 8.

The yoke 23 is provided with internallyscrew-threaded depending lugs 23, to which is secured by screws 28 the cross-piece 29, having a central depending portion 30, with a transverse pin 31, adapted to be received, with portion 30, into a slotted socket 32 in the yoke 33, carrying at its ends the vertical rods 31, which slide in the tubular guide-rods 19, and have at their upper ends heads 35, which serveto prevent the rods 3% from sliding out of the rods 19 by abutting in their downward movement against the headed screwthreaded thimbles or sleeves 36 in the lower ends of rods 19. The upper end of tube 24: tapers inwardly, and within the tube 2% is located a tube 36, split at its upper end and having at its lower end a depending lug or projection 24., upon which turns a cap 37, screwing onto the lower end of tube 24-. The lower carbon 38 is mounted in the split tube 36, and when the latter is pushed up into the tube 2st and the cap 37 is screwed up into place the upper end of tube 36 is contracted and clamps the carbon 38, so as to effectually center and secure it in place. A cylindrical shell or casing 39, contracted at its top so as to form an opening just sufficient to allow the flange of the inner globe 4:0 to enter, screws onto the flange of tube 24.

A ring 451 is located in the space between the casing 39 and the tube 2st and is free to move vertically therein. The ring *tl is provided with pins 12, projecting from its periphery through Vertical slots 13 in the easing 39 and having their ends located in a circumferential groove 41 in the inner surface ofa ring-nut 15, which screws on the shell 39.

The upper surface of the ring 11 inclines upward, and resting thereon are aset of wire coils 16, such as shown in Figs. 10 and 11, arranged in a circle and having their depending ends 46 extending through vertical slots 11 in the ring 11, as shown in Figs. 9 and 12, and engaging the flange 25 of tube 2-1, thereby holding them in place and preventing their movement in a circle, but permitting their movement radially.

It will readily be seen that by means of the foregoing construct-ion upon the ring-nut -15 being screwed up the ring 11 will be carried upward and the wire coils ad justably clamped between the top of casing 39, ring 4 1, and the neck of globe 10, thereby securing the neck of the latter in place, as shown in Figs. 1, 8, and 12. A cap 16 rests on the top of globe 10, through which the carbon feeds.

17 is the outer or main globe, having its neck resting in the flanged socket 48, provided with set-screws 49 for securing the globe to the socket. The socket 418 is secured to the depending portion of cross'piece 29 by a bayonet-joint, one of the slots 50 of the bayonet-joint being shown, which engage and form, with the transverse pin 31, the bayonetjoint operated by turning the socket 1 8.

The globe 47 is provided at its top with a cap 47, which, when the globe is raised to its closed position, compresses the springs -17, mounted on the rods 19, against the bottom of casing 10, thereby aiding in holding the globe steadily in position. The raisingand lowering of the globe 17 and the rods 3st in the rods 19 will be readily understood without further description.

The weight 6 is preferably made of a particular construction, as shown in Figs. 15 and 16. The weight 0 is formed with a socket 51 at its lower end, which maybe provided with slots 52, as shown, to receive and engage the upper end of the carbon 3, the socket- 51 being secured to the weight by a screw 53 or otherwise. The weight isv provided with vertical grooves 51, terminating in a socket at the upper end of the weight, and in the vertical grooves 54: are located delicate springcontacts 56, having their upper ends projecting into the socket 55 and their lower ends bent and clamped between the socket 51 and the weight, as shown. The spring-contacts 56 are bent slightly outward, so that when the weight is located in the tube 2 the springs 56 will bear on the inner surface of tube 2 and secure ample contact for the passage of current.

In Figs. 2 and 3 is shown a modification of the dash-pot for the tube 2. In this construction there are two dash-pots 57, suspended from the ends of a yoke 58, clamped to the tube 2, and pistons 59, secured to the framework 60 below. This modification is inclosed in a casing 61. The advantage of this construction lies in the shortening of the lamp somewhat by a saving of the vertical space taken up by the dash-pot shown in Fig. 1.

In the construction of this lamp a particular arrangement of and provision for ventilating the resistance-coils is provided as follows:

Theouter casing 62 of the lamp is preferably formed with a hood 63 about opposite the lower end of coil 7, and below the hood 63 is an additionalcasing 64, inclosing a set of resistance-coils 65, encircling the portion of the lamp between coil 7 and top of globe 4:7. This resistance is supported in any way desired out of contact with the casing and is included in a branch with the lamp when in use by suitable connections. (Not shown.)

The resistance in the present example is composed of spirals of German-silver wire led around the lamp and mounted on porcelain or other heat-resistin g insulators in the usual way common to such structures and connected in series with the coil 7 and the carbons. Sufficient space is allowed around the resistances for their thorough ventilation,and openings 66 are provided just above the cap 47 for the ingress of cold air and beneath hood 63 for the egress of the heated air which passes through the coils of the resistance.

In the entire construction of the lamp it is understood that insulation is used, as indicated in dark lines, wherever it is needed to prevent the current from taking any other path than that desired.

It may sometimes happen that the carbon 3 will break short off in the tube 2. In such event it would be necessary to remove a por- .move the broken end.

tion of the lamp mechanism in order to re- To avoid the necessity of doing this, a window or opening 18' is provided in the tube 2 above the yoke 18, as shown in Fig. 4, by means of which the broken end of the carbon can be pushed out of tube 2 by inserting a piece of metal through the opening 18.

\Vhat we claim as new, and desire to secure by Letters Patent of the United States, is-

1. In an electric-arc lamp, a central carboncarrying device, a yoke secured thereto, dashpots suspended from said yoke parallel with the carbon-carrying device, and pistons engaging said dash-pots, as set forth.

2. In an electric-arc lamp, the combination, with a tube for receiving and permitting vertical play therein of the upper carbon, of a clutch consisting of a yoke secured to said tube,vertical guide-rods, a cross-piece mounted to slide on said guide-rods, bell-crank levers pivoted to said cross-piece and pivoted at their upper ends to said yoke, and bent so that one bell-crank lever passes on one side of said tube and the other bell-crank lever passes on the other side of said tube, and clamping-jaws pivoted to the lower ends of said bell-crank levers and adapted to clamp the carbon, as set forth.

3. In an electric-arc lamp, a solenoid located centrally in the lamp and having a tubularsolenoid-core, a vertically-movable tube extending through said solenoid-core to which the latter is attached, a clutch mechanism connected to said tube, a carbon vertically movable in said tube, a casing surrounding the magnet-coil, a second casing surrounding the magnet-coil casing, and an air-space between said two casings, and vertical guide rods for the outer globe extending between said casings, as set forth.

4-. In an arc-lamp,a central vertically-movable tube for carrying the upper carbon, a pair of dash-pots yoked to said tube, and pistons for said dash-pots mounted on the main frame, as set forth.

5. In an arc-lamp, a centrally-located inclosed solenoid, a resistance arranged adjacent to and about said solenoid, an outer casin g with an air-space between it and the solenoid-casing and having a hood at its bottom, and a second outer casing below the first outer casing and ventilated at its top and bottom.

6. In an electric-arc lamp, a clutch mechanism consisting of a fixed yoke, vertical guide-rods, a cross-piece vertically movable on said guide-rods, bell-crank levers pivoted to said cross-piece and having horizontal upper portions pivoted to the yoke and bent on opposite sides to the carbon to clear the latter, and rocking clutching-jaws pivoted to the lower ends of the bell-crank levers, as set forth.

7. In an electric-arc lamp, a central vertically-movable support for the upper carbon, in combination with parallel dash-pots yoked to said carbon-support, and arranged on the sides of said support, as set forth.

8. In an electric-arc lamp, a centrally-located movable carbon-carrying tube, a yoke secured thereto, dash-pots suspended from said yoke and parallel with the carbon-carry ing device, and pistons engaging said dashpots; in combination with a solenoid located centrally in the lamp and having a tubular solenoid-core attached to the said verticallymovable carbon-carrying tube which extends through said solenoid-core, a clutch mechanism connected to said tube, a carbon vertically movablein said tube, a casingsurrounding the magnet-coil, a second casing surrounding the magnet-coil casing and forming an air-space between said casings, and vertical guide-rods for the outer globe extending between said casings, as set forth.

9. In an electric-arc lamp, a magnet-coil, a tube extending centrally through said coil, and suspended from its dash-pot, an upper carbon located in said tube, and a tubular solenoid-core surrounding said tube and secured thereto; in combination with a clutch mechanism consisting of a fixed yoke, verti- IIO cal guide-rods, a cross-piece vertically movable on said guide-rods, bell-crank levers pivoted to said cross-piece and having horizontal upper portions pivoted to the yoke and bent 5 011 opposite sides to the carbon to clear the latter, and rocking clutching-jaws pivoted to the lower end of the bell-crank levers, as set forth.

10. In an arc-lamp, a centrally-located mov- IO able tube for carrying the upper carbon, having an openingin its side permitting of access to and removal of the carbon when broken, as set forth.

In witness whereof we have hereunto set our hands this 7th day of May, 1897.

ELIHU THOMSON. CHARLES E. llAR'lllAN. \Vitnesses:

JOHN W. GIBBONEY, HENRY O. Wns'rENDARr. 

